Did you ever arrive a new place that you couldn't stop taking pictures? The last time I felt this way was 6 years ago when I've been in New york City for the first time (I lived in Maine and was only a 7 hours drive to NYC so been there several times). I just couldn't stop myself, those high buildings with historical architecture, the movement in the streets, I was completly fascinated!
Cartagena was the same. Although is a less busy city, the colonial style houses got me quickly, the pastel and vivid colors mixed with whites and wood, I was in photography heaven.